what is real filed from the header ?

What is the meaning of "init a struct with any real field from the header" ?

[Yongjian Feng]

Where did you see this sentence? Need more details.

[Kishan Paladiya]

Thank you for your reply!

I saw this in one of my sample code which is provided by device manufecturer. I implement the code using that sample code. Code is for motor.

[Rik]

The word 'real' can broadly mean two things:

1. Non-complex (i.e. imag(x) is 0)
2. Actually existing (implying that some elements are empty and should be ignored)

Without more context of this code it is difficult to say with certainty, but it is probably the second.

A comment without the code is very difficult to make sense of. Please include a link to the source of this comment. Remember that we can't look on your screen to see what you're doing.

[dpb]

I'd guess it's both 1 & 2

[Kishan Paladiya]

% we need to init a struct with any real field from the header.

dummy_struct = struct('speed' , 0);

The code is look like this. I guess the second one is possible.

[dpb]

Well, the code simply creates a struct with the field 'speed' with a real value (happens to be zero), but by using a literal constant, the existence of any header field of that name is totally irrelevant -- so the comment doesn't appear to match the code on the micro basis, anyway (as, unfortunately, one finds often is true).

>> struct('speed',0)
ans = 
  struct with fields:

    speed: 0
>> 

In the larger context of the overall code it may have some relevance if there's later logic that compares that field to some header structure for which we have no reference, but that's again something that's not knowable simply from the code posted.

So it may well be there is a field 'speed' in some header somewhere and it may turn out that whether the specific field exists or not elsewhere is important, but it's totally immaterial as to the functioning of the above line in isolation.

Context is everything..."location, location, location!" as the mantra goes, and like "peephole" optimizations that try to fine tune code for performance by looking at individual pieces in isolation, trying to interpret overall intent by looking only at single instructions/lines of code is likely as not to miss the larger point in "not seeing the forest for the trees"

[Kishan Paladiya]

Thank you so much, that's what I want. I appreciate and satisfy with this answer.